Punching tool and method of making same



June 24. 1924. 1,499,309

J. H. RAMSEY PUNCHING TOOL ANDMETHOD O F MPK'G SAME Filed 00?.. l2, 1923' 3 Sheets-Sheet 1 4.. ATroRNEYr June 24 1924. 1,499,309`

J. H. RAMSEY PUNCHING TooL AND METHOD 0F MAKING SAME Fi'led oct. 12 192: s sheets-sheer 2 L ATroRNEYs June 24, 1924. 1,499,309

J. H. RAMsEY FUNCHING TOOL AND METHOD OF MAKING SAME Filedl on. 12, i923 s sheets-sheer 5 Patented June 24, 1924. Y

JOSEEH H. RAMSEY, or ALBANY, Yoan, AssIGNoR ronnMsnrcHnIN co, me., Y

QF AnBANmivnw Yoan, n comonerron oF NEW roms;

runen-nwe woon ANI? 'METHOD oF MALKjl-NG SLA-NIE.V

Application sieg peloter 12, 1923, Seria; Nq. segnalo..

To all whom t may concern."

Be it known that I., JosnBH RniyrsEY, a citizen of the United States, residing at Albany, in the County of Albany," Stats 0f New York, have invented certain new and useful lImprovements in Punching Tools and Methods of Making Same; and I do,

hseby declare a@ slewing" fo bie a all, clearJ and exact description of the invention,

such as will enable .others skilled in the art to which it .appertains to make and luse the metal strips which are first punched iorperi forated to provide the pintle openings in properlyl spaced relation. l e

To facilitate the production of thelinks Without Waste from the metal strip lit lis desirable to punch and likewise to blanktwo or more links at each operation. VAs the blanking operation follows that of punching it is essential that the punches .and `dies be,

arranged with extreme accuracy togensure proper register and to avoid inaccuracies in the links which would make the `chain worthless. Furthermore, it is desirable that the dies be removable individually Vfrom the supporting blocks in which they are as- V4f sembled `.to permit repair or re}g lacementy when the pnnches ,or dies are Worn or infihlfssl F91' rsplasmsht hhs relish srdis' must be an exact counterpart @i the .orghlsl site relationship@ the other ril-riches .and

diss- Hsrstofolzs `1111v siderable size. d hardened and bsssuss of lts slzscehsldsrsbls distortion of the die nesulted. ,The eco,-4

opsfsthe Puhh was ,supported 51,11 asimilar block and positioned tolsshnslzsts as elossly' as possible with the die. f Extreme .accuracy Was impossible and rapid Wearing ',of the cutting edges Aof the die usually resulted.`

The punches and dies Werenqt interchangeable with vothers of the samev kind and the wearing a particular die necessitated the making of an: entirely new `lolock and of oooperatingy punches the-renfor.-V Diefmaking is a ,very costly operation and much unnecessaryeXpense yresulted from the `methdd followed making the Adies and punchesl .It is the Object 'of the Present invention to provide pu'nches land dies and a method e ,of making such tools whereby accuracy and exact alignment is ensuredy distortion in hardening is lavoided and interchangeability is secured, so that the cost ofpreparing and replacing punches anddies is reduced to a minimumrand variations in the dimensions of product cut by the dies issubstantially eliminated. l

Other ,objects'and advantages of the invefntionfwillr be apparent vas l is better ,understood by. reference to the following specification and accompanying drawing, .in

Figgl is a diagram indicating the arrangement o v,the perforations yor pintle openings in the metal strip With` the outline of the links,y as infshed Lloyd` :the bla-nking p dies, superposed thereon;

Fig. 2 is a plan View `ofa block with the .perforating dies disposed therein;

Fig. 3 is va Vertical section through the psrfrsthg diss sud Punches; Fig. 4 is a plan View of a block with the blanking dies disposed therein;

,Fig- 5 s a rsrtsal sssfsh through rhs blanking, dies `and punches; ,and l `Fig.6is a vsection en the line 6e-6 of :Fig

The invention Adependsnpon the ntilization to the maximum kpossi-lele ,extent in tool- `making .of boring :and Lturning @relations y the diss 20,1 rehshss- A .circular @nehme is then hsrsd ih ths bloeh :119.011 slsshtsf Fish established hy the rdssiisd Ilsfishs .rs1-P Isf the .settings-dess sf hhs hss A ssssrld opshhehrsrlsrphlg the jflrst is #hss fhsrsd .on another center rvliich is likewise estabs `lished hylths 'desired lslatishship of lhs siits ion openings l establishes a definite angular relation with the axes of the block and furnishes a datum to which all dies and punches Vare finished so that when mounted in the openings they will always assume the same position relatively to each other in the block. The block may be hardened and ground or not as desired; as it is not subject to wear hardening is unnecessary.

. The dies `are next formed .in cylindrical l steel blocks of approximately the diameter of the openings in the supporting blocks, but slightly over-size. 'lf the die openings are circular they are bored in the die block in exact relative position. If the openings are irregular in shape as in the case ofthe blanking dies the block 'is split into two parts and the openings are cut, for example,

by a special milling cut-ter. The die blocks are then hardened, and owing to theirrelatively small size there is no material distortion. After hardening the die blocks are mounted-in a special iixture and ground, first to the exact diameter of the openings in the/supporting block and then at one side so as to provide a flat surface corresponding to the chord of the overlapping openings.

i The angular relation ofthe iiattened surface to the cutting edges ofthe die is fixed so that when the die blocks are mounted in the supporting block the cutting edges of the contiguous dies will be inthe exact relation desired. As all similar die blocks are finished in the same manner and to the same dimensions, they may be duplicated exactly and are interchangeable.

4punch blocks are therefore exact complements of the dies and cooperate with all dies of the same `kind and dimensions.

Referring to the drawing fora more detailed disclosure ofthe invention, 5 indicates (a metal strip from which the links are stamped. The strip is y fed through the stamping machine byy mechanism (not shown) and 'isl first perforated as indicated at 6. Itis to be,understood that the perforations may be of any desired form depending upon the design of the links. For

convenience the perforations are indicated as circular. After perforation the links are blanked from the strip and usually have the "form indicated in dotted lines 7 on Fig. 1.

' The relative positions of 'the punches and dies for perforating and blanking the links are indicated in Fig. 1,'it being desirable t0 punch and to blank two links at each operation. To accomplish'this result successfully it is necessary that the punches and dies4 of each pair bear a definite and predetermined relation to each other, and as hereinbefore the block. The center may be accurately determined by the use of JohansenV gauges or other suitable precision instruments.v A second circular opening 11 is then bored in the block in overlapping relation with the opening 10 and upon a center which is determined and fixed in the same way. These two circular openings have a common chord 12 which is disposed in a definite angular position with reference to the .axes of` the block 8. The chord establishes, therefore, a datum to which all 'dies are finished, and when so finished the dies maybe inserted in the openings andL will assume and maintain a fixed and definite position in the supporting block. Y

The dies 18 and 14 are cylindrical in form and are made from steel blocks. If the openings 15 in the dies are circular they Aare bored in the die blocks in the exact'relative position in which the perforations vare to be made in the metal strip 5. The exact position of the openings may vbe'determined as in the case of the 'openings 10 and 11 in the supporting block. The die blocksV are slightly oversize and are hardened in the usual manner before they are finished. As the die blocks areofrelatively small size the hardening operation does not cause any material distortion. After hardening the cylindrical surfaces of the die blocks are ground until the blocks are of the exact'diameter to fit the openings 10 and 11 in the bloclrS. They are then ground to providel flattened surfaces corresponding to thechord 12, these surfaces being disposed'in exact angular relation to the axes of the die blocks and lthe cutting edges of the openings 15. Suitable fixtures are employed to determine the positionof the flattened sidesof the'diefblocks so that Vevery Vdie Vis al complement of every other,

and whenthe dies are mounted in the block 8 the cutting edges will assume a definite po! The cooperating punches are similarly and are provided with flattened sides'corref sponding to the common chord 'of the circular openings. The angular relation off these flattened sides to the punches 20 is predetermined 'and fixed and when the punch blocks are mounted in the supportingblocks 17 the punches necessarily assume the proper positions to cooperate exactly with the openings 15 in the die blocks 13 `and 14k. When the dies and punches are mounted in the punching` machine they are in exact alignment and perform their intended function With the minimum of Wear. vIn Fig. 3 the punches and dies are shown in assembledv relation With a stripping` plate 21 which ensures Withdrawal of the punches from the strip 5 as it passes between the die blocks and the stripping plate.

The openings in the blanking dies are necessarily irregular in form but the dies are prepared and mounted in substantially the manner hereinbefore described. Thus a supporting block 22 is first finished to the desired dimensions and is bored on kpredetermined centers to provide circular openings 23 and 24 in overlapping relation and having a common chord 25. The die blocks are each made in two parts 26 and 27.- These blocks are first made over-size and the openings 28 are formed in the parts 26 and 27 by means of suitably shaped milling cutters. The blocks are then hardened and are ground to the exact diameter of the openings 23 and 24. Thereafter flattened sides are formed on the die blocks While they are held in assembled relation, the flattened sides I being in exact angular relation to the axes of the blocks and to the cutting edges. The die blocks may then be assembled with' the supporting block 22 and secured thereto by screws 29 or other suitable fastening means.

The cooperating punches are,fas indicated in Fig. 5, mounted in a supporting block 30 Which is providedl with overlapping cir-- cular openings having Va common chord and predetermined centers, the openings kbeing formed by boring as herinbefore described. The punch blocks 31 are formed oversize and are bored to receive the punches 32V which are separately formed and hardened. After the punch blocks have been hardened they are ground to the diameter kof. the openings in the supporting block 30 and'similarly provided With attened faces corresponding to the common chord of the overlapping circles and in exact angular relation With the axes of theblocks and With the ycutting edges of the punches 32. When the punches are assembled YWith' the punch blocks 31gthe cutting edgesfwillbe yin proper relation to cooperate exactly with the cutting edges of the dies. The punches and dies are assembled `in the'machine'with a strippingfplate 33 ydisposed therebetween which ensures r'separation of the punches from the strip 5 as the latter passes-through.v The punches arc'kfprovidedwith leaders 34 Which enter the perforations' in the strip and ensure the centering thereof so that the edges ofthe links Will bear a predetermined relation to the perforations.

From the foregoing it will be observed that I have provided tools for punching metals and a method of preparing such tools which ensures the duplication thereof-With mathematical exactness.k Furthermore, the method, because of the yutilization of inexpensive operations of boring, turning and grinding, ensures the production of the tools with a minimum of expense. The accuracy and interchangeability of the separate tools permit replacement of parts broken or damaged in Luse and avoids losses., which otherwise occur through the necessity of duplicating parts Which are not Worn because other partis have been injured in use.

Various changes may be made in the form and arrangement of the tools and in the details of the method as herein described Without departing from the invention or sacricing any of the advantages thereof.V l I claim 1.111 a punching tool the combination of a supporting block-having'overlapping circular openings with their centers in definite and predetermined relation,and cylindrical blocks having the desired cutting edges with flattened sidesL corresponding to the common `centers in definite and predetermined relation, forming cylindrical blocks having the 'desiredcutting 'edges with flattened sides corresponding to thecommon chord yof the intersecting circular openings and disposed fin definitek relation to the cutting edges whereby .'When the cylindrical blocks are mounted in the circular openings the cutting edges of thecyliiidrical blocks `will bear a definite relation to each other.

llO

` 3. A method ofmaking punching tools,

which comprises boring overlapping circular openings in a support-ing block with their centers in definite and predetermined relation, forming cylindricalblocks having the desired cutting edges, grinding the cylindrical blocks to provide' flattened sides correspondingto the cominonchord of the intersecting circular openings and disposed in delinite relation to the cutting edges Where- Vby when the cylindricalblocks are mounted in the circular openings the cutting edges will bear a delinite' relation to each other. 4. A method' of making punching tools,

I which comprises boring overlapping circular openingsV in a supporting block Withitheir ycentersl in denite and predetermined relation, forming cylindrical blocks havingy the desired cutting edges, hardening and grinding the cylindrical blocks to providerflattened sides corresponding to theU common chord of the intersecting circular openings;v

In testimony whereof I my signature.`

YJOSEPH H. RAMSEY. 

